TsMYB5 genes serve as the core transcription factors responsible for the red and purple leaf pigmentation in Triadica sebifera

In autumn, the leaves of the Triadica sebifera turn yellow, orange, red, or purple, making it an important tree species in garden landscaping. However, the mechanisms governing the different leaf colors of T. sebifera are still not well understood. In the current study, red- and purple-leafed T. sebifera were used as research materials to analyze the mechanism of leaf color differences using transcriptomics and metabolomics. Delphinidin-3,5-di-O-glucoside and cyanidin-3-O-glucoside were found to be the main pigments responsible for red leaves. Based on this analysis, the candidate genes TsMYB5 ( TsMYB5-like1 and TsMYB5-like2 ) were identified. Bioinformatics analysis indicated that TsMYB5-like1/2 belong to the MYB5 clade. Functional analyses in tobacco and T. sebifera demonstrated that TsMYB5-like1/2 promote anthocyanin production. Using yeast two-hybrid and firefly luciferase complementation assays, we confirmed that TsMYB5-like1/2, TsEGL3, and TsTTG1 mutually interact to form the MBW complex. Luciferase assay indicated that TsMYB5-like1/2 independently activate TsDFR and TsANS expression, and that the activation effect of TsMYB5-like1/2-TsEGL3-TsTTG1 complexes is stronger. These results offer novel perspectives on the mechanisms underlying the distinct leaf coloration of T. sebifera and provide a theoretical basis for the breeding and improvement of variegated T. sebifera . • TsMYB5-like1/2 is positively correlated with Dp3,5 G and Cn3G. • TsMYB5-like1/2 belongs to MYB5-type R2R3-MYB, which promotes anthocyanin biosynthesis. • The TsMYB5-like1/2-TsTTG1-TsEGL3 complex activates TsDFR and TsANS promoter expression.